The present invention relates to a remote controlled electronic apparatus equipped with a standby power source kept in an active state even when the electronic apparatus is not in operation.
Most of the recent electronic apparatus are equipped with a light sensor to receive incident light modulated by infrared rays for example, and have a remote control function for operating the electronic apparatus by receiving the infrared rays radiated from a remote controller. In order to utilize such a remote control function, a standby power source is provided therein for holding required data even when the electronic apparatus is not in operation, including the on/off state of a main power source for the electronic apparatus, information relative to a timer for the apparatus, and further manipulative information.
For the purpose of curtailing the standby power, there has been known heretofore a method of setting a controlling microcomputer of the electronic apparatus in a sleep mode at its reception standby time to thereby reduce the power consumption. When the electronic apparatus is placed in a reception standby state, a sleep mode is selected to stop the entire functions of the controlling microcomputer by halting its clock. This mode is used frequently in view of energy saving. When a specific signal is inputted in case the controlling microcomputer is in such a sleep mode, the controlling microcomputer is reset automatically to the former state in response to the input signal. Reset to the former state from the sleep mode is termed xe2x80x9cwake-upxe2x80x9d.
The electronic apparatus is placed in its reception standby state by a control signal transmitted from a remote controller, and then the controlling microcomputer is placed in a sleep mode. In this sleep mode, there may arise a problem that, if any noise derived from external light of a fluorescent lamp or the like is received, such noise may be recognized erroneously as a control signal. In this case, the controlling microcomputer is caused to wake up, and the power is supplied thereto for enabling the microcomputer to decode a remote control signal, whereby it is rendered impossible to achieve the principal purpose of reducing the power consumption in the reception standby mode.
It is therefore an object of the present invention to accomplish improvements in a remote controlled electronic apparatus, wherein a control signal is supplied via a filter to a control unit, and the filter is actuated in a reception standby mode so as to prevent a microprocessor, which is in a low power state, from being reset by any external light noise, hence suppressing the power consumption. Further, when the controlling microcomputer has been reset to its operating state, the filter is opened so that the apparatus is enabled to respond to a remote control signal.
In the improvement, a plurality of filters may be prepared in such a manner as to be selectively switchable and enhanced functionally in the case of any erroneous operation or malfunction due to some noise, whereby setting can be so performed as to comply with ambient noise in the environment around the electronic apparatus, hence minimizing the erroneous operation and suppressing the power consumption in the reception standby mode.
According to a first aspect of the present invention, there is provided a remote controlled electronic apparatus which comprises a filter for attenuating a noise component included in a remote control signal, and a control unit for decoding the remote control signal transmitted via the filter. In this apparatus, when the remote control signal has been decoded and regarded as a power cutoff instruction, the control unit demagnetizes a relay to place the electronic apparatus in its reception standby mode and to set itself in a low power state, and then outputs a filter control signal to actuate the filter.
According to a second aspect of the present invention, there is provided an electronic apparatus wherein, upon detection of a fixed-width pulse included in a remote control signal, a control unit is caused to wake up from a low power state and then outputs a filter control signal to halt the function of a filter.
According to a third aspect of the present invention, there is provided an electronic apparatus which comprises a filter for attenuating a predetermined frequency component of a remote control signal composed of a fixed-width pulse and a succeeding control code, and a control unit for decoding a remote control signal supplied via a first input terminal, wherein, when the control signal has been regarded as a power cutoff signal, a relay is demagnetized to place the apparatus in its reception standby mode and to set itself in a low power state, thereby disabling the first input terminal from accepting the remote control signal. And in response to the fixed-width pulse included in the remote control signal supplied via the filter at a second input terminal, the control unit releases itself from the low power state and enables the first input terminal to accept the remote control signal again.
According to a fourth aspect of the present invention, there is provided an electronic apparatus wherein, if a control code is not existent within a predetermined time after a release from a low power state to wake up the control unit, another filter control signal is outputted to further enhance the noise eliminating function of the filter, and then the control unit is placed in the low power state again.
According to a fifth aspect of the invention, there is provided an electronic apparatus wherein its low power state is such that a clock or execution of an instruction is at a halt in a control unit.
According to a sixth aspect of the invention, there is provided a remote control method for an electronic apparatus. The method comprises a step of decoding a remote control signal composed of a fixed-width pulse and a succeeding control code; and a step of executing, upon decision that the decoded control signal is a power cutoff instruction, predetermined attenuation of a noise component superposed on the remote control signal to set a control unit in a low power state, and a step of demagnetizing a relay to place the apparatus in a reception standby mode.
According to a seventh aspect of the invention, there is provided a method for remote control of an electronic apparatus by detecting a fixed-width pulse included in a remote control signal, and then releasing the control unit from its low power state while stopping the action of attenuation.
According to an eighth aspect of the invention, there is provided a method for remote control of an electronic apparatus, comprising a step of decoding a remote control signal supplied via a first input terminal and, upon decision that the decoded control signal is a power cutoff instruction, demagnetizing a relay to place the apparatus in a reception standby mode and to set a control unit in a low power state, and disabling the first input terminal from accepting the remote control signal; a step of attenuating a predetermined frequency component of the remote control signal; and a step of making a decision as to whether a fixed-width pulse included in the attenuated remote control signal is existent or not and, upon detection of the fixed-width pulse, releasing the control unit from the low power state and enabling the first input terminal to accept the remote control signal again.
And according to a ninth aspect of the invention, there is provided a method for remote control of an electronic apparatus by releasing the control unit from a low power state to wake up the same and, if a control code is not existent within a predetermined time after such wake-up, outputting another filter control signal different from one filter control signal to thereby further enhance the attenuation of noise, and then placing the control unit in the low power state again.
The above and other features and advantages of the present invention will become apparent from the following description which will be given with reference to the illustrative accompanying drawings.